Optimal preventive maintenance for a fleet of dump trucks with two-dimensional lease contract

This paper develops a mathematical model of optimal preventive maintenance for a two-dimensional lease contract of a fleet of dump trucks. The lease contract coverage is characterized by two parameters - age and usage. We use one dimensional approach to model the age and usage of a repairable equipment. The lessor will provide preventive maintenance and corrective (CM) actions during the contract period, and a penalty cost incurred when the time required to perform an imperfect repair (CM) exceeds a target. This strategy will reduce equipment failures and hence it decreases the penalty cost and maintenance cost during the lease contract. We find the optimal maintenance degree and time between preventive maintenance, which minimizes the expected total cost.